As the above high-pressure washing liquid ejecting washing apparatus, there has been proposed an apparatus in which a holder attached with a plurality of high-pressure washing liquid ejecting nozzles arranged is rotated (moved in a circular shape) or pivoted in a conical shape to eject a high-pressure washing liquid from the washing apparatus to objects in a direction perpendicular to the objects, thereby washing surfaces of the objects with the high-pressure washing liquid ejected from the ejecting nozzles (e.g., see Japanese Patent No. 2705719). This apparatus includes convergent nozzles which eject the high-pressure washing liquid in a single straight-line shape.
Commonly, nozzles used in the conventional washing apparatus are cone-type nozzles ejecting a washing liquid spreading in a conical shape or fan-type nozzles ejecting a washing liquid spreading in a sector shape. When these nozzles are used, it is not necessary to rotate the holder in a circular shape or pivot it because a jet of the washing water diffuses with a great width, unlike the apparatus disclosed in the above publication.
On the other hand, the washing apparatus in the above publication uses the convergent ejecting nozzles ejecting the washing liquid in a single straight-line shape without diffusing, and therefore, an energy density of the ejected washing liquid is very high and is several tens times as high as that of the cone-type nozzles or the fan-type nozzles. This can remove the contaminants on the washed surface and wash the objects very effectively. However, regions (areas) of the objects to which the washing liquid is applied are very small, and only localized regions are washed. In other words, regions to which the washing water is not applied are large and these regions cannot be washed.
As a solution to this, the present inventors discovered a high-pressure washing liquid ejecting washing method and apparatus in which a plurality of high-pressure washing liquid ejecting nozzles eject a washing liquid in a single straight-line shape to the objects to wash them, while moving the objects at a constant speed, the high-pressure washing liquid ejecting nozzles are arranged on a common holder to be spaced apart from each other and are oriented in the same direction so as to face the objects, and the high-pressure washing liquid ejecting nozzles are rotated integrally with the holder to eject the high-pressure washing liquid to the objects and filed a patent application (Japanese Patent Application No. 2007-281322).
As another prior art associated with the above washing apparatus, there is disclosed a washing apparatus including a detector means for detecting specified regions attached with more contaminants than those of other regions within surfaces of the objects, a retaining means for retaining the objects in a tilted state along a direction in which the objects are conveyed, a conveyor means for conveying the objects retained by the retaining means in the conveying direction, a discharge means for discharging a washing liquid to the surfaces of the objects, and a moving means for moving the discharge means along a width direction of the objects which is orthogonal to the conveying direction, within the surface of the object, and the discharge means selectively discharges the washing liquid to the specified regions (see for example, Japanese Laid-Open Patent Application Publication No. 2006-10947).